AUTOCERT LOGO (see external-dns) Autocert issues X.509 certificates from your own internal certificate authority and auto-mounts them in kubernetes containers so services can use TLS. Autocert is a kubernetes add-on that integrates with `step certificates` to automatically issue X.509 certificates and mount them in your containers. It also automatically renews certificates before they expire. Diagram / Video Autocert certificates let you secure your data plane (service-to-service) communication using mutual TLS (mTLS). Services and proxies can limit access to clients that also have a certificate issued by your certificate authority (CA). Servers can identify which client is connecting improving visibility and enabling granular access control. Once certificates are issued you can use mTLS to secure communication in to, out of, and between kubernetes clusters. Services can use mTLS to only allow connections from clients that have their own certificate issued from your CA. It's like your own Let's Encrypt, but you control who gets a certificate. ## Getting Started These instructions will get `autocert` installed quickly on an existing kubernetes cluster. ### Prerequisites Make sure you've [`installed step`](https://github.com/smallstep/cli#installing) version `0.8.3` or later: ``` $ step version Smallstep CLI/0.8.3 (darwin/amd64) Release Date: 2019-01-16 01:46 UTC ``` You'll also need `kubectl` and a kubernetes cluster running version `1.9` or later: ``` $ kubectl version --short Client Version: v1.13.1 Server Version: v1.10.11 ``` You'll also need [webhook admission controllers](https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/#admission-webhooks) enabled in your cluster: ``` $ kubectl api-versions | grep "admissionregistration.k8s.io/v1beta1" admissionregistration.k8s.io/v1beta1 ``` We'll be creating a new kubernetes namespace and setting up some RBAC rules during installation. You'll need appropriate permissions in your cluster (e.g., you may need to be cluster-admin). ``` TODO: Check whether you have cluster permissions..? GKE instructions here if you don't have them. ``` In order to grant these permissions you may need to give yourself cluster-admin rights in your cluster. GKE, in particular, does not give the cluster owner these rights by default. You can give yourself cluster-admin rights by running: ``` kubectl create clusterrolebinding cluster-admin-binding \ --clusterrole cluster-admin \ --user $(gcloud config get-value account) ``` ### Install You can install `step certificates` and `autocert` in one step by running: ``` curl https://github.com/smallstep/... | sh ``` If you don't like piping `curl` to `sh` (good for you) you can also [install manually](INSTALL.md) then return here to complete the quick start guide. ### Enable autocert To enable `autocert` for a namespace the `autocert.step.sm=enabled` label (the `autocert` webhook will not affect namespaces for which it is not enabled). To enable `autocert` for the default namespace run: ``` $ kubectl label namespace default autocert.step.sm=enabled ``` To check your work you can check which namespaces have `autocert` enabled by running: ``` $ kubectl get namespace -L autocert.step.sm NAME STATUS AGE AUTOCERT.STEP.SM default Active 59m enabled ... ``` ### Annotate pods In addition to enabling `autocert` for a namespace, pods must be annotated with their name for certificates to be injected. The annotated name will appear as the common name and SAN in the issued certificate. To trigger certificate injection pods must be annotated at creation time. You can do this in your deployment YAMLs: ``` $ cat < Annotations: autocert.step.sm/name: sleep.default.svc.cluster.local autocert.step.sm/status: injected Status: Running <... snip ...> Init Containers: autocert-bootstrapper: Image: step-k8s/bootstrapper <... snip ...> Containers: sleep: Image: alpine <... snip ...> Mounts: /var/run/autocert.step.sm from certs (ro) /var/run/secrets/kubernetes.io/serviceaccount from default-token-jn988 (ro) autocert-renewer: Image: step-k8s/renewer <... snip ...> Volumes: certs: Type: EmptyDir (a temporary directory that shares a pod's lifetime) <... snip ...> Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled 4m2s default-scheduler Successfully assigned sleep-f996bd578-nch7c to docker-for-desktop Normal SuccessfulMountVolume 4m2s kubelet, docker-for-desktop MountVolume.SetUp succeeded for volume "certs" Normal SuccessfulMountVolume 4m2s kubelet, docker-for-desktop MountVolume.SetUp succeeded for volume "default-token-jn988" Normal Pulled 4m1s kubelet, docker-for-desktop Container image "step-k8s/bootstrapper" already present on machine Normal Created 4m1s kubelet, docker-for-desktop Created container Normal Started 4m kubelet, docker-for-desktop Started container Normal Pulled 4m kubelet, docker-for-desktop Container image "alpine" already present on machine Normal Created 4m kubelet, docker-for-desktop Created container Normal Started 3m59s kubelet, docker-for-desktop Started container Normal Pulled 3m59s kubelet, docker-for-desktop Container image "step-k8s/renewer" already present on machine Normal Created 3m59s kubelet, docker-for-desktop Created container Normal Started 3m59s kubelet, docker-for-desktop Started container ``` Certificates are mounted to `/var/run/autocert.step.sm`. We can inspect this directory to make sure everything worked correctly: ``` $ kubectl exec -it sleep-f996bd578-nch7c -c sleep -- ls -lias /var/run/autocert.step.sm total 20 1593393 4 drwxrwxrwx 2 root root 4096 Jan 17 21:27 . 1339651 4 drwxr-xr-x 1 root root 4096 Jan 17 21:27 .. 1593451 4 -rw------- 1 root root 574 Jan 17 21:27 root.crt 1593442 4 -rw-r--r-- 1 root root 1352 Jan 17 21:41 site.crt 1593443 4 -rw-r--r-- 1 root root 227 Jan 17 21:27 site.key ``` The `autocert-renewer` sidecare installs the `step` CLI tool, which we can use to inspect the issued certificate: ``` $ kubectl exec -it sleep-f996bd578-nch7c -c autocert-renewer -- step certificate inspect /var/run/autocert.step.sm/site.crt Certificate: Data: Version: 3 (0x2) Serial Number: 46935033335539540860078000614852612373 (0x234f5bce23705f015a8377ab1cfd5115) Signature Algorithm: ECDSA-SHA256 Issuer: CN=Autocert Intermediate CA Validity Not Before: Jan 17 21:41:04 2019 UTC Not After : Jan 17 21:46:14 2019 UTC Subject: CN=sleep.default.svc.cluster.local Subject Public Key Info: Public Key Algorithm: ECDSA Public-Key: (256 bit) X: 31:aa:a1:7f:c8:b4:c6:da:90:fc:b8:3a:e9:cc:48: f9:89:b9:5d:d7:a4:63:80:76:9f:21:6d:e5:88:4c: a8:e4 Y: ed:21:38:57:cd:3f:32:71:6f:ca:81:34:b0:4a:bd: a3:c4:8d:d1:87:bc:2c:4c:42:79:e5:35:49:38:3f: b7:c8 Curve: P-256 X509v3 extensions: X509v3 Key Usage: critical Digital Signature, Key Encipherment X509v3 Extended Key Usage: TLS Web Server Authentication, TLS Web Client Authentication X509v3 Subject Key Identifier: 43:0E:0A:50:30:A5:5B:AF:22:AC:28:49:26:53:2A:B4:D4:20:E0:E0 X509v3 Authority Key Identifier: keyid:61:45:1E:E4:95:4C:0A:6B:37:4C:43:41:FD:54:2E:8E:5E:A2:24:EF X509v3 Subject Alternative Name: DNS:sleep.default.svc.cluster.local Signature Algorithm: ECDSA-SHA256 30:44:02:20:0c:c5:ab:0d:22:17:a2:04:9f:ff:5f:b1:c0:a5: 8b:94:88:e0:40:66:e1:19:e9:34:2f:67:74:12:4f:bb:51:8b: 02:20:01:7e:0d:44:ce:b2:92:41:d5:78:0d:02:5a:68:05:7c: c2:a9:81:28:71:5c:95:6d:56:51:49:e0:37:b7:09:87 ``` ### Test your installation To test your installation you can install the `hello-mtls` demo app. * Install app, which uses mTLS and responds "hello, `identity`" * Do a `kubectl run` of `step-cli` then get a certificate using `step` and `curl hello-mtls` from within the cluster * Port forward from localhost to get a certificate then `curl` with `--resolve` ### Further reading * Link to ExternalDNS example * Link to multiple cluster with Service type ExternalDNS so they can communicate ### Uninstall * Delete the `sleep` deployment (if you created it) * Remove labels (show how to find labelled namespaces) * Remove annotations (show how to find any annotated pods) * Remove secrets (show how to find labelled secrets) * Delete `step` namespace